The necessity for an exceptionally smooth ride in emergency ambulances has long been recognized by medical attendants who serve in them. Many enroute procedures must be performed quickly, and among these are certain procedures requiring a significant amount of skill and accuracy. Commonly used techniques such as the insertion of an intravenous drip needle become extremely difficult in a rough-riding vehicle, and control of hemorrage is frequently rendered impossible. These and related problems can seriously interfere with the efforts of the medical crew to save the patient when time factors are critical.
An adequately smooth-riding suspension for such vehicles is clearly a necessity. The design of an appropriate suspension, however, is further complicated by the fact that the loading of the ambulance, particularly over the rear wheels, is a variable factor, being determined by the number of personnel and patients and/or passengers being carried. This virtually mandates the use of a variable compliance suspension, which in turn, for cost reasons at the present state of the art, restricts the designer to an air suspension, wherein the air spring compliance and extension may be controlled by varying the pressure to accommodate varying loading conditions.
Various types of air suspensions have been proposed and used for vehicles in attempts to improve load bearing and riding characteristics. Such equipment is in general heavy, reducing the amount of payload which can be carried. Moreover, these previous systems have been expensive to fabricate and are not readily adaptable to a variety of vehicle constructions, including small bodied vans and trucks which are presently popular. An exception to the foregoing is disclosed in U.S. Pat. No. 4,379,572 issued Apr. 12, 1983 to the inventor of the improved system to be described herein.
It is a feature of the present invention to provide a light weight relatively inexpensive air suspension system improving on the features of the above-referenced patent. Such a system would be a substantial benefit to emergency vehicles and the care offered in connection with such vehicles. It would also be usable in connection with recreational vehicles to improve their ride and handling, as well as with any other type of van or similar motor vehicle.